Grass mowing equipment typically includes a mower deck having a fixed cutting width of 32 inches or more. In many applications it is desirable to have a mower that can cut a relatively wide path of grass to efficiently handle large lawns and fields. Commercial landscapers may prefer to use the largest width mower deck in order to cut the grass in as short a time as possible. The cost and time of mowing can be substantially reduced by using a mower with a wide cutting path.
Some areas of grass may be enclosed by a fence having only a narrow gate or passageway for entering and exiting the area. Grass mowing equipment also may need to travel over narrow bridges or underpasses. Additionally, grass mowing equipment may need to move on public roadways, or be carried on vehicles or trailers, that have width limitations. Therefore, it may be impractical or impossible to use a mower having a relatively wide fixed width mower deck in these applications. Instead, only lawn mowers having smaller width mower decks, such as less than 32 or 36 inches, may be needed for such applications. The narrow cutting width may decrease mowing efficiency and increase the time for mowing.
Grass mowing equipment used to cut large areas may have three or more rotary cutting blades under the deck. The deck width may depend on the length of each rotary cutting blade, and the position and configuration of the cutting chambers under the deck. The blades may be positioned in cutting chambers that cut grass in overlapping swaths so that no uncut strip is left. For example, a mower deck with three cutting blades may have a center cutting blade positioned in front of, and overlapping with, the left and right cutting blades.
U.S. Pat. No. 6,308,503 relates to a convertible width lawn mower having a rotatable wing section pivotally attached to the mower deck. The wing section can move between a substantially horizontal operating position and a substantially vertical non-operating position. The wing section may be manually rotated upwardly and secured in the vertical position so that the effective width of the mower deck may be reduced. The cutting blades are automatically disengaged from the engine when raised from a mowing position to a transport position. The danger posed by the raised wing section's exposed cutting blade, may be reduced by including a safety device or interlock to prevent the cutting blade from being driven by the engine when the wing section is raised. Additionally, a caster wheel attached to the wing section may be pivoted out of the way when the wing section is raised to the transport position. The convertible width lawn mower does not cut grass when the mower deck wing section is raised to the narrowed, transport position.
A grass mowing machine is needed with a mower deck that may be narrowed in width without disengaging the cutting blades from the engine. A grass mowing machine is needed that can be used for cutting grass at two or more different deck widths. A mower deck is needed having a variable cutting width.